Treatment of products or goods of or containing cellulose derivatives



Patented Feb. 9, 1932 I UNITED STATES RENE GLAVE, OI BASEL-AUGST, NEAR BASEL, SWITZERLAND TREATMENT OF PRODUCTS OR GOCDS OF OR CONTAINING CEELLULOSE DERIVATIYES No Drawing. Application filed January '14, 1926f, Serial No. 81,322; and in'Germany September 26, 1925.

This invention relates to improvements in the restoration of lustre to delustred threads, yarns, fabrics, or other products made of or containing cellulose acetate.

Cellulose acetate goods can be delustred by treatment in boiling soap baths or in 'acid' baths. Thus by the use of baths containing an organic acid, woolly effects can be produced by a control of the concentration and temperature of the bath and the duration of the treatment, the volume or bulk of the goods being increased to 3 to 5 times their original volume. In this way a lustrous cellulose acetate fabric can be converted into a fabric that is both lustreless and more bulky in character. These lustreless fabrics, whether dyed or undyed, or containing other natural or artificial fibres, present an entirely new character approximating to that of woollen goods. Hitherto it has been necessary, for the productionof a figured fabric (partly lustrous and partly lustreless) to make a mixed fabric containing a textile material which is not affected by boiling soap solutions or by acids. By this method, a figured fabric of an attractive character can be obtained, but the. manufacture of the goods is expensive and complicated, and important economies would be effected if the same results could be produced by a simpler method.

This result could be obtained if after delustring the whole of the cellulose acetate D goods it were possible to restore to. a lustrous condition the part or parts constituting the design, pattern or figure.

.Again it sometimes happens that, owing to carelessness of the dyer in watching the concentration ortemperature of the acid, part of the goods becomes delustred. A similar defect sometimes arises fromthe goods coming into contact with thesteam pipes used for heating purposes. Defective goods of this character are unsalable and a method of restoring partly delustred goods to a lustrous condition would be of great value.

fter many experiments it has been discovered that the lustre of cellulose acetate goods can be restored by theuse of substances that are capable of forming a solution with cellulose acetate (whether such solution be a liquid solution or a solid solution), that is to say, substances which act as solvents or swelling .agents for cellulose acetate, and

afterwards steaming the goods preferably under pressure.

As solvents or swelling agents may be used I the organic acids (acetic, formic, etc.) employed for delustring purposes, and also alcohols, esters and salt solutions, e. g. a solution of calcium sulphocyanide.

The steaming operation is effected with aid of steam at a pressure in excess of the atmosphere. The pressures used may range up to 5 atmospheres absolute or even higher, always provided that the temperature is not so high as to melt or damage the cellulose acetate oods.

Apparently the relustred goods retain to a large extent the increased volume or bulk produced b the delustring process to which the were rst subjected.

F igured and other partly lustrous and partly lustreless goods of a very attractive character are produced by applying to a delustred fabric a printing paste or a stencilling or like preparation containing a solvent or swelling agent, and afterwards steaming the goods, so that the fabrics are relustred at the parts to which the paste is applied. In this way, brilliant and effective figures may be produced on a dull ground.

preferably yes or mordants may be added to the relustring astes so that different colour effects can also e obtained.

Relustring may also be effected by wholly or partiall v immersing the goods, in, or other-- wise treating'the goods with, baths containing a solvent or swelling agent, to which may be added if desired dyestu s, salts, mordants, or protective colloids, separately or in combination. After a suitable interval, the goods are removed, Fuickly dried and sub- ]ected to the action 0 steam.

Preferably, baths containing a weak solution of an organic acid are used, but if stronger solutions are used, the steamin operation may be shortened or even omitted,

the goods being simply dried after removal from the bath. I

In certain cases, notably where the celluesigns or' lose acetate fibre contains residual solvent, for

example, when a solvent of high boiling point has been employed in the manufacture of the fibres, treatment with solvent or swelling agents may be omitted, and lustre may be restored by the application of steam alone to the delustred goods. A lustre can thus be obtained closely resembling that of natural silk, the goods nevertheless retaining to a large extent, the bulky or voluminous character imparted by the original delustring operation. In steaming defective goods, the relustring of the delustred parts is accompanied by partial delustring of the lustrous parts, so that goods of a uniform lustre are obtained, this effect being probably due to the fact that the steam used for relustring, though substantially free from water in the form of condense or mist, may, nevertheless, carry traces of water which can act as a delustring agent for the fully lustred portions of the goods until a state of equilibrium is reached. f course, if steam carrying large quantities of condense or mist, that is to say, a mixture of steam and water, were applied to the fabric, it would act as a delustring agent in the same way as boiling water or boiling soap solutions.

Example I Piece goods of delustred cellulose-acetate are printed with a paste made by emulsifying together 650 grams of gum arabic (50%) with 300 cc. of ethyl alcohol and 15 grams of Rhodulin orange. The printed goods are well dried, steamed at a pressure of 1.4 atmospheres absolute, and finally cold washed. The pattern then comes up as a lustrous figure on a lustreless ground.

Example I I Delustred cellulose acetate yarn in the form of hanks is partly immersed in a bath containing 0.5% of acetic acid, and maintained at a temperature of 50 C. After one-half to one hour, the yarn is removed, centrifuged, dried and steamed for half an hour under pressure. i

It will be understood that the process is not limited to the procedure set forth in the preceding examples, but maybe varied within wide limits without departing from the invention.

, What I claim and desire to secure by Letters Patent is 1. A process of imparting lustre to delustred material comprising cellulose acetate and a substance capable of forming a solution with cellulose acetate, which comprises subjecting the material to the action of dry steam. I 2. A process of imparting lustre to delustred material comprising cellulose acetate, which comprises treating the material with a substance capable of forming a solution with cellulose acetate, and afterwards subjecting the material to the action of dry steam.

3. A processof imparting lustre to delustred material comprising cellulose acetate, ,whichcomprises treating the material with an aqueous preparation containing a substance capable of forming a solution with cellulose acetate, and afterwards subjecting the material to the action of dry steam.

4. A process of imparting lustre to delustred material comprising cellulose acetate, which. comprises treating the material with an aqueous solution containing a solvent for cellulose acetate, and afterwards subjecting the material to the action of dry steam.

5. A process for imparting lustre to delustred material comprising cellulose acetate, which comprises treating the material with an aqueous solution of acetic acid, and afterwards subjecting the material to the action of dry steam.

6. A process of imparting lustre to delustred material comprising cellulose acetate, which comprises treating the material with a substance capable of forming a solution with cellulose acetate, and afterwards drying the material and subjecting the same to the action of dry steam. 7. A process of imparting lustre to delustred material comprising cellulose acetate, which comprises treating the material with an aqueous preparation containing a substance capable of forming a solution with cellulose acetate, and afterwards drying the material and subjecting the same to the action of dry steam.

8. A process of imparting lustre to delustred material comprising cellulose acetate, which comprises treating the material with an aqueous solution of a solvent for cellulose acetate and afterwards drying the material and subjecting the same to the action of dry steam.

9. A process of imparting lustre to delustred material comprising cellulose acetate, which comprises treating the material with an aqueous solution of acetic acid, and afterwards drying the material and subjecting the same to the action of dry steam.

10. A process for the manufacture of fig ured and other lustrous effects on delustred cellulose acetate material, which comprises applying to selected areas of the delustred material a substance capable of forming a solution with cellulose acetate, and after- .wards subjecting the material to the action jecting the material to the action of dry steam.

12. A process for imparting a lustre resembling that of natural silk to yarns, threads, fabrics or other material comprising delustred cellulose acetate filaments containing a substance capable of forming a solution with cellulose acetate, which comprises subjecting the material to the action of dry steam.

In testimony whereof I have hereunto subscribed my name.

RENE CLAVEL. 

